Synchronized Swept-Sine: Theory, Application, and Implementation - October 2015
Effect of Microphone Number and Positioning on the Average of Frequency Responses in Cinema Calibration - October 2015
The Measurement and Calibration of Sound Reproducing Systems - July 2015
Nonlinearities in Loudspeaker Ports
The increasing demand for high SPL at low frequencies has prompted the study of nonlinearities in loudspeaker ports. At high levels, ports produce jets of air, display acoustic compression, loss and distortion, generate turbulence noise, and rectify pressure fluctuations. These phenomena are measured and analyzed. A simplified nonlinear model of a port is presented. Flared ends and gentle tapering help somewhat. The low-level linear acoustic characteristics of ports of varying cross-section are analyzed. The velocity profiles of ports are measured, and a new theory for this and the associated nearfield pressure is presented, which contradicts the usual "piston-in-a-baffle" approach.
Click to purchase paper or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $20 for non-members, $5 for AES members and is free for E-Library subscribers.